1. Field of the Invention
The invention relates to surgical control devices. More particularly, the invention relates to surgical control devices which are operatively connected to a main control unit and remotely situated within the surgical arena at some distance from the main control unit.
2. Description of the Prior Art
Remote hand controls have become a necessary accessory for operation of certain surgical devices which are situated within the operating room and must be controlled from the sterile field. An example of such a device is an irrigation pump used during arthroscopic surgical procedures. This pump is an electrically controlled console located in a "non-sterile" environment in the operating room while the patient is located in a "sterile" environment in the operating room. The pump is connected via tubing to the patient but, because of the distance of the pump from the patient, direct operation or control of the pump console is impractical. The pump, being away from the sterile environment where the surgical procedure is being performed, requires a remote control for the surgeon to manually control and adjust pump features and settings. This control should preferably be a small, lightweight remote hand control unit and should not only be able to withstand exposure to disinfectants but should also be autoclavable for sterilization purposes after each use. The autoclavability requirement means the device should be capable of withstanding exposure to approximately 275.degree. F. (121.degree. C.) repeatedly for over 1000 cycles in order to be commercially viable (expecting a minimum of 1600 cycles is not unheard of).
Some prior art surgical remote controls which are not autoclavable can only be used in an operating room if they are enclosed in a transparent plastic bag which may obviate the need for autoclaving the unit after use. This method is cumbersome and clearly not the method of choice and an autoclavable remote would be preferred.
While autoclavable remote hand controls are known and were originally designed to be hermetically sealed and intended to be sterilized using autoclave procedures, success with such remotes has been less than expected because they usually fail after relatively few uses, i.e. autoclave cycles. A common prior art design incorporates an array of domed snap-switches on a printed circuit board encased within a silicone jacket. The thickness of the jacket over the switches is often less than elsewhere on the unit thus sometimes enabling air to permeate the jacket during an autoclave cycle. The expansion and contraction of such "permeated" air and any air trapped within the jacket during manufacture causes such remotes to fail. During the high temperatures of the autoclaving process, the jacket may expand due to its permeability and heating of the residual air within the remote. This air then creates a negative pressure after cooling, sometimes forcing the snap domes to activate or become dislodged. Additionally, some remotes are also large, heavy and bulky in size, thus making them difficult to handle during use. Since surgeons prefer to clamp the remote to a surgical drape, smaller and lighter units are preferable.
Due to the premature failures of the known autoclavable remote hand controls, there is a need for a reliable lightweight surgical remote control that can withstand repeated autoclave cycles.
It is accordingly an object of this invention to produce an autoclavable remote control unit which is reliable over a commercially reasonable number of autoclave cycles.
It is another object of this invention to produce an autoclavable remote control unit which is small, lightweight and easily manipulated by the user with one hand.
It is also an object of this invention to produce an autoclavable remote control unit which is usable without having to be bagged during use.
It is still another object of this invention to produce an autoclavable remote control unit capable of activating a switch element within a hermetically sealed housing by means of non-contiguously activating the switch element from without the housing.